1. Technical Field
The features described herein relate generally to the field of computerized devices and wireless networking. More particularly, the disclosure is directed to improved in-device coexistence (IDC) interference detection and mitigation.
2. Description of Related Technology
Many wireless-enabled user devices are equipped with a number of different radio technologies co-located on a single hardware platform. Common examples of such wireless devices include, but are not limited to laptop computers, smartphones, and tablet computers, such as the exemplary Macbook™, Macbook Pro™, Macbook Air™, iPhone™, and iPad™ manufactured by the Assignee hereof. Typical configurations of multi-radio wireless user devices consist of one or more wide-area radio access technologies such as Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE) Worldwide Interoperability for Microwave Access (WiMAX), Code-Division Multiple Access (CDMA-2000), as well as shorter-range or personal area network (PAN) wireless technologies such Bluetooth (BT) and wireless local areas networks (WLAN), such as e.g., the IEEE 802.11-based standards, operating in Industrial Scientific Medical (ISM) frequency bands. In addition, the wireless user device may include a Global Navigation Satellite Systems (GNSS), GLONASS, or Global Positioning Satellite (GPS) receiver for positioning.
Common applications of the co-located multi-radio platforms include for example: (i) voice calls received on UMTS relayed to a BT headset, (ii) the audio portion of streaming video received on LTE relayed to the BT headset, (iii) Wi-Fi data access/Wi-Fi offloading, (iv) Wi-Fi router functionality, and GNSS receiver operation to support location-based services. When these radios operate simultaneously in adjacent or overlapping Radio Frequency (RF) spectrum, resultant interference may occur from transmission of one radio to the reception of the other radios. This situation is often referred to as “In-Device Coexistence” or IDC interference. For example, IDC interference may occur between UMTS/LTE and the ISM-band radios when the frequency separation between the bands is less than 50 MHz. With a frequency separation of less than 20 MHz, typically 50 decibels (dB) of isolation is required between radios to avoid IDC effects. Mobile wireless devices implementing a small form factor typically provide, only 10-30 dB isolation between the multiple radios. Thus, mobile devices implementing such small form factors may experience a degradation of performance on the radios experiencing IDC interference.
However, a prior art cellular base station serving the mobile device is not aware that the mobile device is experiencing an IDC interference condition (the latter which is not readily detectable at the base station). Thus, transmissions to and from the base station may be degraded, or cause degradation of the performance of other active radios used by the mobile device.
Accordingly, improved solutions are required to mitigate IDC interference without degrading the performance of each of the wireless access systems co-located on the wireless device.